The invention relates to a device for preventive detection of faults in a load connected to an AC electrical power supply system by means of a switching means comprising a first switch, a device comprising control means for the switching means, the control means comprising means for identifying the type of load, means for detecting faults with test means to temporarily connect the load to test power supply means, and means for measuring the current in the load.
A known device (EP-A-581,078) comprises an optic circuit for detection of connection of a plug in a socket connected to an electrical power system. It then performs fault detection by measuring the current in the load when the latter is supplied under low power, either by a pulse generator or by the electrical power system via a step-down transformer. This document indicates that it is possible to detect the type of load, and more particularly the fact that the load is purely dissipating or not, from measurement of the current when the test power supply in constituted by a pulse generator. It does not, however, provide any details on how this detection is performed. In practice, the device described does not really enable the nature of the load to be identified and fault detection is not adapted to the type of load.